Drip inhibiting glue nozzle

ABSTRACT

A glue dispensing nozzle has a nozzle face with an orifice and a surface tapering outwardly and downwardly of the orifice to terminate in a flat circular rim. The nozzle has a bore in which resides a spring-loaded plunger having surfaces cooperating with a valve seat in the bore to seal off the flow of glue to the orifice. An end of the plunger extends through the orifice and forwardly of the rim so as to engage a workpiece and effectively open the nozzle as the nozzle moves further toward the workpiece. When the nozzle is retracted from the workpiece, excess glue on the nozzle face is dispersed over the tapering surface and the flat circular rim to inhibit dripping therefrom.

- United States Patent [1 1 Dieter 1 Feb. 12, 1974 1 1 DRIP INHIBITINGGLUE NOZZLE Primary ExaminerAllen N. Knowles Assistant ExaminerGene A.Church 75 l t l A. D t t Oh i nven 0r Ju Ian e er Cmcmna lo Attorney,Agent, or Firm-Wood, Herron & Evans [73] Assignee: R. A. Jones andCompany, Inc.,

Covington, Ky. Filed: Sept. 27, 1972 App]. No.: 292,771

[57] ABSTRACT A glue dispensing nozzle has a nozzle face with an orificeand a surface tapering outwardly and downwardly of the orifice toterminate in a flat circular rim. The nozzle has a bore in which residesa spring-loaded plunger having surfaces cooperating with a valve seat inthe bore to seal off the flow of glue to the orifice.

An end of the plunger extends through the orifice and forwardly of therim so as to engage a workpiece and effectively open the nozzle as thenozzle moves further toward the workpiece. When the nozzle is retractedfrom the workpiece, excess glue on the nozzle face is dispersed over thetapering surface and the flat circular rim to inhibit drippingtherefrom.

13 Claims, 4 Drawing Figures DRIP INHIBITING GLUE NOZZLE This inventionrelates to dispensing nozzles and particularly to work-actuated nozzlesfor sequentially dispensing glue onto a plurality of workpieces and forpreventing dripping between dispensing operations.

In the packaging art, it is common to form and erect cases or cartonsfrom blank material. Typically, the material is cut into appropriatelyshaped blanks which are scored and folded into cases. Glue is dispensedonto tabs or flaps of a partially erected case, and these members arethen folded and pressed against other cooperating tabs or flaps tosecure the case in its final form.

A pattern of glue is dispensed onto the case blanks by a plurality ofwork-actuated nozzles supported in a glue head. Such nozzles arenormally screwed into the glue head and comprise bodies having aninternal passage communicating with a glue source in the head. Eachnozzle terminates in a flat face having a glue dispensing orificenormally closed by a spring-loaded plunger extending through the orificeand downwardly from the flat face. In operation, the head and itsnozzles are lowered toward a case blank positioned beneath the head. Asthe head is lowered, the plungers engage the blank and, as each nozzlecontinues downwardly, the nozzle orifices are thereby opened to dispenseglue. The head is then withdrawn while a glued blank is removed and afresh blank is conveyed under the head.

As the head is withdrawn, each plunger is urged downwardly to close itsrespective nozzle orifice. Between the time the head and the nozzle faceare withdrawn and the time when the plunger shuts off the glue flow,some glue flows through the orifice and down the plunger. Glue escapingduring this closure time runs down the plunger and forms a drop on theplungers end. This drop can be so large as to drip from the plunger ontoa case blank or conveyor beneath the head. Such drips occur prior toproper positioning of a succeeding case blank and are thus deposited oncase surfaces not intended to be glued or on the blank conveyor.Dripping is a major problem between cycles as, for example, when theoperation is stopped for some period of time. These drops respectivelydetract from the cases appearance and can foul the carton erectingapparatus.

It has thus been one object of this invention to provide a dripinhibiting dispensing nozzle.

A further object of this invention has been to provide a drip inhibitingglue nozzle having means for dispersing glue, flowing through a nozzleorifice during closure time, over a relatively large nozzle area.

. The objectives of the invention are attained by providing a shallow,concave surface in the lower end of the nozzle surrounding the gluedispensing orifice. The nozzle face comprising this surface tapersoutwardly and forwardly .of the orifice and terminates in a flat,circular rim. A spring-loaded plunger resides in the pasis lifted fromthe workpiece and the time when the plunger seats to seal the gluepassage, some glue escapes through the orifice. Rather than run down theplunger, however, the excess glue tends to spread itself around theconcave nozzle face and eventually forms a ring about the flat rim.While the total amount of glue on the rim would be sufficient to form alarge drop if suspended from a small area, such as the plunger end, theglue is spread over the much larger area of the rim and does not driptherefrom.

These and other objects and advantages will become apparent from thefollowing detailed description and drawings in which:

FIG. 1 is a cross-sectional view of a dispensing nozzle, according tothe invention, in retracted position over a workpiece;

FIG. 2 is a cross-sectional view similar to FIG. 1 but showing thenozzle in a projected glue dispensing positron;

FIG. 3 is a cross-sectional view similar to FIGS. 1 and 2 but showingthe nozzle in a partially retracted position; and

FIG. 4 is an end view taken along lines 4-4 of FIG. 1 and omitting theplunger.

Referring now specifically to the drawings, there is shown in FIG. 1 aglue nozzle 10 according to the specific embodiment of the invention.The glue nozzle 10 includes a nozzle body 11 having external threads 12.These threads are provided so that the glue nozzle can be screwed into agluing head (not shown) together with a plurality of similar nozzles soas to provide a preselected pattern of nozzles and, respectively, ofglue dots onto a workpiece. The nozzle body 11 includes an internal andgenerally axial glue passage or bore 13 which communicates with a sourceof glue in the head. Toward the lower end of the nozzle, the bore 13defines a valve seat 14. The bore 13 terminates downstream of valve seat14 at an orifice'or opening 15.

A valve stem or plunger 16 is disposed within the bore 13. The plunger16 has surfaces 17 designed to cooperate with the valve seat 14 in orderto seal bore 13 against the passage of gluetherethrough. The plunger 16is urged into sealing position by a spring 18. The spring 18 ispositioned between the plunger 16 and a nut 19 which is screwed intothebore 13 by way of threads 20 at the upper end of the bore 13. The nut19 has a passageway 21 theret hrough for the passage of glue. An end 22of the plunger extends downwardly from the orifice 15 so as to becapable of engaging a workpiece C and unseating surfaces 14 and 17 toallow glue to flow from the nozzle and onto the workpiece, which can bea case or carton blank or any other material to be glued.

The nozzle 10 further comprises a nozzle face which includes a taperingsurface 30 and a flat rim surface 31. The surface 30 tapers outwardlyand downwardly of the orifice 15 at approximately 10 with respect to thescrewed into the glue head, it is normally held in a vertical positionso that the plane of the flat rim 31 is generally horizontal. Of course,the surface 30 could be slightly curved rather than having a straighttaper. In

any event, it provides a concave surface surrounding the orifice.

It can be appreciated that the Hat rim could be omitted and the concaveface could terminate in a sharp circular edge. Provision of the flatrim, however, has several advantages including the provision of morearea to enhance the adhering properties of the nozzle face. Also, theflat face does not mark the blank and the glue heads movement does nothave to be critically controlled to avoid blank marking or cutting.

By way of example, the preferred embodiment includes a nozzlethirteen-sixteenths inches in length. The orifice has a one-eighthinchdiameter. The flat rim 3] is concentric with the orifice, isapproximately 0.015 inch in width and is approximately 0.250 inch inoutside diameter. The nozzle face tapers upwardly and outwardly from theflat rim and terminates in a hexagonal configuration comprising sixflats 33, opposite ones of which are about one-half inch apart.

In a normal case-preparing operation, a plurality of nozzles such as theone shown in the drawings are screwed by way of their external threads12 into a gluing head such that the passages 21 and bores 13 of thenozzles communicate with a source of glue in the head. In a typicalgluing apparatus, four or five glue nozzles are positioned within thehead such that when actuated they apply a pattern of four or five gluedots to a case blank disposed beneath the head. Of course, any number ofnozzles could be used as required. The head is mounted to reciprocatedownwardly toward the blank so that the plunger end 22 and the rim 31 ofthe nozzle actually engage the blank C, as in FIG. 2, and dispense gluethereon.

Since the end 22 of the plunger extends beyond the rim 31, it engagesthe blank C and stops while the nozzle body continues downwardly againstthe plunger spring bias. The glue passage thus is opened to allow glueto flow into the cavity formed by the blank C on the bottom and the domeor tapering surface 30 of the nozzle face on the top. When the nozzle israised, a uniform dot of glue remains on -the blank.

After a predetermined time, the head is reciprocated upwardly, to theposition shown in FIG. 1, and the glued blank is removed while anotherblank is conveyed into proper glue-receiving position. The head isnormally operated in the range of 8-35 cycles per minute so that theoperation has an output of 8-35 cases per minute. Typically, theapparatus may be operated to handle 30 cases per minute wherein thecases dwell under the glue head for glue application for one second andduring another second a glued case is removed and a new blank positionedunder the withdrawn or retracted head.

FIG. 3 illustrates a glue nozzle in an intermediate position as it israised from case blank. In this position, it can be seen that the rim 31does not engage the case blank but the end 22 of the plunger 16 stillengages the blank C so that the plunger surface 17 does not engage thevalve seat 14. As a result, some glue is transmitted through the valveand the orifice to the nozzle face.

When the apparatus is operated at a speed of, for exam- 7 always escapesthe valve and resides on the valve face.

This excess glue tends to spread itself about the tapered surface 30.Some of the glue eventually gathers on the flat rim 31 in the form of aring as in FIG. 3. Since the glue is dispersed over a relatively largesurface area including the tapered surface and the flat rim, ascontrasted with that of the plunger end 22, surface tension between theglue and the surfaces is sufficient to maintain the glue thereon andit-does not drip off.

When the head is again reciprocated downwardly toward a succeedingblank, as shown in FIG. 2, the rim 31 contacts the blank and any excessglue thereon remaining from the previous application is deposited ontothe blank. Thus, over a period of successive operations at a givenspeed, the amount of excess glue, left on the nozzle face when it isretracted from a blank, is generally the same and it is deposited on thesucceeding case blank in the operation. This effectively prevents anexcessive accumulation or build-up of glue on the nozzle face and theglue does not run down the plunger stem to form a large drop which couldfall off onto a case or the conveyor beneath the glue head, and thusfoul the apparatus.

Should the apparatus be stopped for a relatively long period of time,most of the excess glue will eventually gather on the flat rim. Due,however, to the relatively large surface area of-the rim the glue isnormally effectively dispersed and will not drip.

Although the preferred embodiment of the invention has been described asapplied to a work actuated nozzle, the invention has equal advantageousfeatures in other types of nozzles as can be appreciated.

While we have described herein the preferred embodiment of theinvention, many other objects and advantages will become'readilyapparent to those of ordinary skill in the art without departing fromthe scope of the invention, and the applicant intends to be bound onlyby the appended claims.

Having described my invention, I claim:

1. Apparatus for applying glue to objects and including a glue nozzlehaving a body, a vertical bore in said body terminating in an orifice atthe lower end thereof, and a plunger reciprocably mounted in said boreand seating adjacent said orifice to control the flow of glue throughsaid orifice, the improvement comprising a shallow concave surfacesurrounding said orifice at the lower end of said nozzle to minimizedripping or residual glue from said nozzle after each gluing operation,said plunger extending through said orifice and'forwardly of saidconcave surface so that when said nozzle is moved toward an object saidplunger engages said object to unseat.

2. Apparatus as in claim 1 wherein said shallow concave surface extendsoutwardly. and downwardly from said orifice and terminates in a flatcircular rim.

3. Apparatus as in claim 2 wherein said orifice lies in a first planeand said surface tapers downwardly from said plane at approximately a 10angle with said plane.

4. Apparatus as in claim 2 wherein said orifice lies in a first planeand wherein said rim lies in a second plane parallel to said firstplane.

5. Apparatus as in claim 4 wherein said plunger extends outwardly fromsaid nozzle and beyond said second plane.

6. Apparatus as in claim 5 wherein said rim contacts said object whensaid nozzle is moved further toward said object and wherein said rimthereafter disengages from said object when said nozzle is moved awayfrom said object and prior to both disengagement of said plunger fromsaid object and seating of said plunger in said bore.

7. Apparatus as in claim 6 wherein glue is dispensed from said orificebetween the time when said rim disengages from an object and the timewhen said plunger disengages from the object so as to seat in said bore.

8. Apparatus as in claim 7 wherein said dispensed glue is dispersed oversaid concave surface and forms a ring on said flat rim.

9. Apparatus as in claim 2 wherein said orifice has a radius and whereinthe width of the tapering nozzle face between the orifice and the rimisapproximately equal to said radius.

10. Apparatus for applying glue to objects and including a glue nozzleof the type having a body, a vertical bore in said body terminating inan orifice at the lower end thereof, and a plunger reciprocably mountedin said bore and seating adjacend said orifice to control the flow ofglue through said orifice, the improvement comprising a shallow concavesurface surrounding said orifice at the lower end of said nozzle tominimize dripping of residual glue from said nozzle after each gluingoperation, said shallow concave surface extending outwardly anddownwardly from said orifice and terminating in a flat circular rim,said plunger extending beyond said rim so that when said nozzle is movedtoward a workpiece said plunger engages said workpiece to unseat as saidnozzle moves toward said workpiece.

11. Apparatus as in claim 10 wherein said rim engages said workpiecewhen said nozzle is moved further toward said workpiece and thereaftersaid rim disengages from said workpiece when said nozzle is withdrawnand prior to disengagement of said plunger with said workpiece.

12. Apparatus as in claim 11 wherein glue is dispensed from said orificebetween the time when said rim disengages from a workpiece and the timewhen said plunger disengages from the workpiece so as to seat in saidbore.

13. A glue nozzle as in claim 12 wherein said dispensed glue isdispersed over said concave surface and forms a ring on said flat rim.

1. Apparatus for applying glue to objects and including a glue nozzlehaving a body, a vertical bore in said body terminating in an orifice atthe lower end thereof, and a plunger reciprocably mounted in said boreand seating adjacent said orifice to control the flow of glue throughsaid orifice, the improvement comprising a shallow concave surfacesurrounding said orifice at the lower end of said nozzle to minimizedripping or residual glue from said nozzle after each gluing operation,said plunger extending through said orifice and forwardly of saidconcave surface so that when said nozzle is moved toward an object saidplunger engages said object to unseat.
 2. Apparatus as in claim 1wherein said shallow concave surface extends outwardly and downwardlyfrom said orifice and terminates in a flat circular rim.
 3. Apparatus asin claim 2 wherein said orifice lies in a first plane and said surfacetapers downwardly from said plane at approximately a 10* angle with saidplane.
 4. Apparatus as in claim 2 wherein said orifice lies in a firstplane and wherein said rim lies in a second plane parallel to said firstplane.
 5. Apparatus as in claim 4 wherein said plunger extends outwardlyfrom said nozzle and beyond said second plane.
 6. Apparatus as in claim5 wherein said rim contacts said object when said nozzle is movedfurther toward said object and wherein said rim thereafter disengagesfrom said object when said nozzle is moved away from said object andprior to both disengagement of said plunger from said object and seatingof said plunger in said bore.
 7. Apparatus as in claim 6 wherein glue isdispensed from said orifice between the time when said rim disengagesfrom an object and the time when said plunger disengages from the objectso as to seat in said bore.
 8. Apparatus as in claim 7 wherein saiddispensed glue is dispersed over said concave surface and forms a ringon said flat rim.
 9. Apparatus as in claim 2 wherein said orifice has aradius and wherein the width of the tapering nozzle face between theorifice and the rim is approximately equal to said radius.
 10. Apparatusfor applying glue to objects and including a glue nozzle of the typehaving a body, a vertical bore in said body terminating in an orifice atthe lower end thereof, and a plunger reciprOcably mounted in said boreand seating adjacend said orifice to control the flow of glue throughsaid orifice, the improvement comprising a shallow concave surfacesurrounding said orifice at the lower end of said nozzle to minimizedripping of residual glue from said nozzle after each gluing operation,said shallow concave surface extending outwardly and downwardly fromsaid orifice and terminating in a flat circular rim, said plungerextending beyond said rim so that when said nozzle is moved toward aworkpiece said plunger engages said workpiece to unseat as said nozzlemoves toward said workpiece.
 11. Apparatus as in claim 10 wherein saidrim engages said workpiece when said nozzle is moved further toward saidworkpiece and thereafter said rim disengages from said workpiece whensaid nozzle is withdrawn and prior to disengagement of said plunger withsaid workpiece.
 12. Apparatus as in claim 11 wherein glue is dispensedfrom said orifice between the time when said rim disengages from aworkpiece and the time when said plunger disengages from the workpieceso as to seat in said bore.
 13. A glue nozzle as in claim 12 whereinsaid dispensed glue is dispersed over said concave surface and forms aring on said flat rim.